“Alvin Dworman, the owner of a Market Street building proposed as the new headquarters for Twitter, gave sharply discounted office space in the same building to former Mayor Gavin Newsom’s campaign for lieutenant governor — a political contribution valued at more than $11,000, campaign finance records show.

Weeks after the gift last fall, Newsom officials aided negotiations between Twitter and Dworman by offering the Internet company a payroll tax freeze as an incentive to move into Dworman’s building, a 1 million-square-foot art deco structure at 1355 Market St. once known as the San Francisco Mart.“